/Engine/Plugins/Importers/USDImporter/Source/USDClasses/Public/USDAssetUserData.h
AssetImportData assigned to Unreal materials that are generated when parsing USD Material prims
[UCLASS](Programming/UnrealArchitecture/Reference/Classes#classdeclaration)() class UUsdMaterialAssetUserData : public [UUsdAssetUserData](API\Plugins\USDClasses\UUsdAssetUserData)
TMap<FString, ...
ParameterToPrimvar
In the context of our reference materials that just read a single texture for each material parameter, this describes the primvar that the USD material is sampling for each texture.
TMap<FString, ...
PrimvarToUVIndex
In the context of our reference materials that just read a single texture for each material parameter, this describes the Unreal UV index that will be used for sampling by each USD primvar.